[Significance of multivesicular bodies in synthetic cell processes].

Phosphatase-positive and -negative multivesicular bodies (mvb) are discernable by ultrastructural and ultracytochemical findings. The phosphatase-negative mvb are actually not considered to belong to the group of lysosomes. Because, they are obviously involved in synthesizing the cell-specific lamellated bodies (i.e. multilamellated bodies of type II alveolarepithelium cells, keratinosomes, praemelanosomes). By studying the literature about ultrastructural findings in tumors we found that mvb are generally increased in number in tumor cells. The changes in structure of the tumor cell membrane might be interpreted in a way that the synthesizing ability of mvb would generally provide phospholipoproteins to adjust a structural steady state of cell membranes. Our findings suggest that the synthetical activities of the mvb are coupled with multi-enzyme complexes of the vesicle membranes. Obviously, these membranes originate fro the Golgi-apparatus being closely related to the smooth endoplasmic reticulum.